/*
 * Copyright 2006 The Android Open Source Project
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */


// TODO: add unittests for all these operations

#ifndef SkOSFile_DEFINED
#define SkOSFile_DEFINED

#include <stdio.h>

#include "include/core/SkString.h"
#include "include/private/base/SkTemplates.h"

enum SkFILE_Flags { kRead_SkFILE_Flag = 0x01, kWrite_SkFILE_Flag = 0x02 };

FILE *sk_fopen(const char path[], SkFILE_Flags);
void sk_fclose(FILE *);

size_t sk_fgetsize(FILE *);

size_t sk_fwrite(const void *buffer, size_t byteCount, FILE *);

void sk_fflush(FILE *);
void sk_fsync(FILE *);

size_t sk_ftell(FILE *);

/* * Maps a file into memory. Returns the address and length on success, NULL otherwise.
 * The mapping is read only.
 * When finished with the mapping, free the returned pointer with sk_fmunmap.
 */
void *sk_fmmap(FILE *f, size_t *length);

/* * Maps a file descriptor into memory. Returns the address and length on success, NULL otherwise.
 * The mapping is read only.
 * When finished with the mapping, free the returned pointer with sk_fmunmap.
 */
void *sk_fdmmap(int fd, size_t *length);

/* * Unmaps a file previously mapped by sk_fmmap or sk_fdmmap.
 * The length parameter must be the same as returned from sk_fmmap.
 */
void sk_fmunmap(const void *addr, size_t length);

/* * Returns true if the two point at the exact same filesystem object. */
bool sk_fidentical(FILE *a, FILE *b);

/* * Returns the underlying file descriptor for the given file.
 * The return value will be < 0 on failure.
 */
int sk_fileno(FILE *f);

/* * Returns true if something (file, directory, ???) exists at this path,
 * and has the specified access flags.
 */
bool sk_exists(const char *path, SkFILE_Flags = (SkFILE_Flags)0);

// Returns true if a directory exists at this path.
bool sk_isdir(const char *path);

// Like pread, but may affect the file position marker.
// Returns the number of bytes read or SIZE_MAX if failed.
size_t sk_qread(FILE *, void *buffer, size_t count, size_t offset);


// Create a new directory at this path; returns true if successful.
// If the directory already existed, this will return true.
// Description of the error, if any, will be written to stderr.
bool sk_mkdir(const char *path);

class SkOSFile {
public:
    class Iter {
    public:
        // SPI for module use.
        SK_SPI Iter();
        SK_SPI Iter(const char path[], const char suffix[] = nullptr);
        SK_SPI ~Iter();

        SK_SPI void reset(const char path[], const char suffix[] = nullptr);
        /* * If getDir is true, only returns directories.
            Results are undefined if true and false calls are
            interleaved on a single iterator.
        */
        SK_SPI bool next(SkString *name, bool getDir = false);

        static const size_t kStorageSize = 40;

    private:
        alignas(void *) alignas(double) char fSelf[kStorageSize];
    };
};

#endif
